CNC machining is among the most popular methods for manufacturing parts and products. However, to keep overall costs down, manufacturers need to be aware of the factors that influence the cost of CNC machining.
Whether starting with this manufacturing process or planning to scale, it’s essential to know the design factors that influence overall CNC machining costs. So let’s explore some of the critical aspects:
The more complex the shape of a part, the more time it will take to machine. The cost of CNC machining for manufacturing is directly proportional to the time to make the cuts. Thus, always simplify the shape of your part if possible to minimise the manufacturing cost.
In addition, if the component is large, the manufacturing cost will be higher due to the amount of material that needs to be removed. Moreover, the type of tooling used also significantly impacts the manufacturing cost. For example, high-speed steel (HSS) tools are less expensive than carbide tools, but they also wear out more quickly. So, it’s essential to consider the life of the tool when making your decision.
Materials Used in CNC Machining Parts
The type of material being machined also impacts the manufacturing cost. Softer materials such as aluminium and brass are machined relatively quickly and inexpensively, while more rigid materials such as steel and titanium are more expensive to machine.
In addition, not all CNC machines are created equal. The size, speed, and capabilities of the machine will directly impact the manufacturing cost. Larger, faster machines will typically be more expensive than smaller, slower ones.
The tighter the tolerances of a component, the more time it will take to machine and the higher the manufacturing cost. The reason being equipment needs to be operated at a higher precision to achieve the desired tolerance.
The image is used for illustration purposes. KARV Automation is not the owner or creator of the image. (Image Source: Daniel Smyth on Unsplash)
Tight tolerances should only be used if the parts interface with each other. If the components are not going to be assembled, then it is acceptable to have looser tolerances to save on manufacturing costs. Aim to maintain the tolerance accuracy of up to +/-0.02mm to 0.1mm.
Custom Tooling Design
If a part requires custom tooling, the manufacturing cost will be higher. Again, it is because custom tooling takes time and effort to design and fabricate. It may be necessary to order the tooling from a third-party supplier in some manufacturing scenarios.
Depending on the manufacturing requirements, you need to add multiple custom toolings to speed up the overall production process. However, this additional tooling will increase the upfront cost.
CNC Machining Time and Labour
The cost of manufacturing is also affected by the time it takes to machine the part. The more time it takes to make the cut, the higher the manufacturing cost. Labour costs also play a role in the overall cost of CNC machining parts. If a component requires significant setup time or multiple setups, the labour cost will be higher.
Designs that require multi-axis machining or intricate detailing also require more time and labour, which will drive up the manufacturing cost. In addition, complex multi-axis machining often requires manual post-processing and fabrication, which can add high costs to the manufacturing.
Manufacturing Scale and Batch Size
Another critical factor that affects the manufacturing cost is the batch size. Larger batches can lower per-part cost, while smaller ones will have a higher per-part price. But, again, it is due to the overhead costs associated with setting up and running the machine.
To achieve the best price for your parts, it is essential to consider the batch size and manufacture in larger quantities. However, if you only produce a few pieces, it may not be economical to create them using CNC machining.
CNC machining importance can’t be understated as it’s among the widely-used methods. By keeping these above factors in mind, manufacturers can optimise their production and scale faster.